This invention relates to the storage of physical media volumes, such as magnetic tape cartridges or optical disk cartridges, in an automated data storage library having a virtual server, and, more particularly, to tracking physical media volumes in, and added to, partitions of the library.
Automated data storage libraries store large numbers of physical media volumes of data, such as magnetic tape cartridges or optical disk cartridges, for the use of host data processing systems. In one example, a magnetic tape cartridge automated data storage library stores over 6,000 cartridges. Typically, some of the data stored in the library becomes obsolete or less likely to be requested or updated. As the result, some of the physical media volumes are removed out of the library and are archived. The space made available in the library due to the removed physical media volumes is quickly replaced by xe2x80x9cSCRATCHxe2x80x9d volumes, which are typically inserted at an I/O station. The SCRATCH volumes are considered to be blank, and data is recorded thereon as desired by the attached host data processing systems. The physical media volumes are typically identified by means of volume serial numbers, or VOLSERs, which may be read by media sensors. As one example, the VOLSER may comprise a label placed on the cartridge which is read by a bar code reader. As another example, the VOLSER may be recorded in an RF chip in the cartridge which is read by an RF receiver.
Many automated data storage libraries are partitioned so as to appear as multiple libraries. They may be called xe2x80x9cvirtual librariesxe2x80x9d or xe2x80x9cnative librariesxe2x80x9d and in the case of tape libraries, each virtual library is controlled by a xe2x80x9cVirtual Tape Serverxe2x80x9d, or xe2x80x9cVTSxe2x80x9d, and the media is classified into the various virtual or native partitions by ranges of VOLSERs. The physical media volumes are each capable of storing a plurality of logical volumes. A host may directly manage physical volumes in a xe2x80x9cnativexe2x80x9d library, and manages logical volumes as though they were native library physical volumes. The VTS may comprise part of a library manager, and manages the storage of the logical volumes on the physical media volumes. Thus, when the host manages the logical volumes, it does not directly see or control the virtual library physical media volumes. The partitioned libraries, which may comprise both native and virtual library partitions, typically share an I/O station, and, as SCRATCH volumes are provided at the I/O station, the library manager of the automated data storage library will use a VOLSER range table to assign the physical media volumes to the appropriate partition.
Host systems control the native physical volumes and VTS logical volumes, and typically assign those volumes to specific categories. Examples comprise xe2x80x9cSCRATCHxe2x80x9d, which means that the volume is to be treated as though it is blank; xe2x80x9cPRIVATExe2x80x9d, which means that the volume has data for a specific partition or host system; or xe2x80x9cEJECTxe2x80x9d; which means that the volume is being removed from the library.
A newer capability is the export and import of physical media volumes, where particular data, such as logical volumes, is exported on physical media volumes, which may later be imported back into the library. In one example, the physical media volumes containing logical volumes are ejected for the purpose of archiving, and, subsequently, as in disaster recovery, the exported logical volumes are required to rebuild the data of the host systems. Thus, at the time that the logical volumes are imported, the host systems may be aware that the physical media volume is an import volume, and may be aware of the logical volumes stored on a physical media volume, and the partition to which it belongs. Two new categories are provided, xe2x80x9cEXPORTxe2x80x9d, meaning that the data is to be saved for removal from the library; and xe2x80x9cIMPORTxe2x80x9d, which means that the physical media volume may have active data, and is being brought back into the library. However, previously, the host systems had no capability for directly managing the physical media volumes.
Thus, when physical media volumes are provided at an input/output (I/O) station, the library assigns the volumes as UNASSIGNED. An operator, presumably the person who put the volumes in the I/O station, must bring up a program and a display screen to select whether each physical media volume is an IMPORT volume or is an INSERT volume, and assign it to the appropriate category.
This manual operation opens up a point of possible operator error where the operator may incorrectly assign the physical media volume to the wrong category.
Next, the operator may need to decide whether each of the physical media volumes in the IMPORT category is one that is desired by the host system or is one that is not to be an IMPORT volume for one of the present partitions after all, and should be placed in an EJECT category and saved, or changed to an INSERT volume to potentially become a SCRATCH volume.
Again, this manual operation opens up a point of possible operator error where the operator may incorrectly assign the physical media volume to the wrong category.
Once the correct categories have been assigned, the library manager may assign the data to the virtual library and the host may utilize the logical volumes.
Either manual operation error will result in the data of the erroneous SCRATCH volumes being overwritten and destroyed by the host systems. An imported volume is likely to be the only source of the needed data, and the error may lead to the inability to recover from a disaster situation.
An object of the present invention is to provide accurate management of the categories of physical media volumes in virtual and native library partitions of an automated data storage library.
Disclosed are an automated data storage library, method, and a computer program product, for managing physical media volumes, the physical media volumes each capable of storing a plurality of logical volumes. The automated data storage library is partitioned into a plurality of virtual libraries, and comprises a plurality of storage shelves for storing the physical media volumes; at least one input station for receiving physical media volumes; at least one media sensor for sensing the VOLSER of the physical media volumes; at least one interface coupled to at least one host system; at least one drive unit; at least one accessor for accessing the physical media volumes and transporting the physical media volumes amongst the storage shelves, the input station, and the drive unit; and a library manager coupled to the media sensor the interface, and the accessor.
The library manager comprises at least one computer processor providing an inventory of the physical media volumes identifying media categories, and, upon receipt of a physical media volume at the input station, receives the sensed VOLSER of the physical media volume; places the physical media volume in an xe2x80x9cUNASSIGNEDxe2x80x9d category of the inventory identified for a predetermined one of the virtual libraries; and sends an unsolicited message at the interface to the host system, the message identifying the sensed VOLSER and indicating that the physical media volume has transitioned to the xe2x80x9cUNASSIGNEDxe2x80x9d category.
The library manager additionally responds to an assignment message from the host system; assigning the physical media volume from the xe2x80x9cUNASSIGNEDxe2x80x9d category to a defined category, the defined categories comprising (1) an xe2x80x9cIMPORTxe2x80x9d category comprising a physical media volume having active logical volumes, and (2) an xe2x80x9cINSERTxe2x80x9d category comprising a physical media volume which may have no active data; and sends an unsolicited message to the host system, the message indicating that the physical media volume has transitioned to the assigned defined category. The xe2x80x9cINSERTxe2x80x9d category physical volume is then assigned to a virtual library or a native library partition based on a VOLSER range table.
Additionally, the library manager may identify any change in assignment of the physical media volume to further defined categories, such as xe2x80x9cEXPORT-HOLDxe2x80x9d and xe2x80x9cEJECTxe2x80x9d categories, wherein the xe2x80x9cEXPORT-HOLDxe2x80x9d category comprises a physical volume expected to be transferred from the library as having potentially active logical volumes, and the xe2x80x9cEJECTxe2x80x9d category comprises a physical media volume which is being transferred from the data storage library. The library manager then sends an unsolicited message to the host system indicating that the physical media volume has transitioned to the further defined category.